Fire screen unit for volatile liquid storage receptacles



Dec. 4;, 1934. J, TQKHEIM 1,983,417

FIRE SCREEN UNIT FOR VOLATILE LIQUID STORAGE RECEPTACLES Filed Dec. 1, 1930 67 rank/ham,

50 the present device.

Patented Dec. 4, 1934.

UNITED STATES PATENT OFFICE 1,983,417 FIRE SCREEN UNIT Foe: VOLATILE LIQUID STORAGE RECEPTACLES John J. Tokheim, Cedar Rapids, Iowa ApplicationDecember 1, 1930, Serial No. 499,399- g 2 Claims. (01. 220 ss This invention relates to the art of storing volatile, inflammable'liquids, and has in view to provide improved means for connection with storage receptacles for such liquids to protect the 5. contents of the receptacles against fire.

As is well known, it is necessary to vent volatile liquid receptacles of any appreciable capacity, such as gasoline storage tanks and the like, in order to permit the relief of pressures andpartial vacuums which may tend to develop in-such receptacles. It follows, therefore, that in the eventof a fire in the vicinity of a vented volatile liquid storage receptacle, and in the absence of means to preventv flame from reaching the con- 15. tents of the receptacle through-the vent opening thereof, the contents of the receptacle are'extremely likely to become ignited. Accordingly, the general object of the present invention-is to provide a device which, is constructed to permit free venting of a storage receptacle with which the same may be used; and which'is effective to prevent any flame from reaching the contents of the receptacle through the vent opening thereof.

Another object of the invention is toprovide a device of the character mentioned which isof simple, inexpensive construction, which is strong and durable and fully capable of withstanding any explosive forces to which the same may be subjected in use, which is adapted for outside use,

where it may be'exposed'to the elements, and

' which is thoroughly reliable and efficient use.

With the foregoing and other objects in view, the invention consists in the novel featuresof construction, combination and arrangement of parts as will be hereinafter more fully described,

' illustrated in the accompanying drawing and defined in the appended claims.

In the drawing, wherein like characters of reference denote corresponding parts in the different 4 Views:- I

Figure 1 is a vertical section through a relief valve for volatile liquid storage tanks showing the present fire screen device operatively connected therewith.

Figure 2 is an end view of the present device.

Figure 3 is an enlarged detail section through a portion of the present device; and

Figure 4 is an enlarged elevation of one of the numerous duplicate plate elements included in While the present fire screen device may be used in conjunction with volatile liquid storage receptacle relief valves of various different types, and may, in fact, be directly connected with a 5 as storage receptacle in covering relation to the vent opening therein, the same, according to the embodiment thereof illustratedin the drawing, is especially adapted for use in conjunction with relief valves of the type illustrated in my copending application Serial Number 353,833. Accordingly, said device has been illustrated in the present instance as being disposed in covering relation to the vapor outlet and air inlet opening of a reliefvalve of the type disclosed in my said copending application. It will be understood, 5 however, that this has been done merely to bring out the utility of the device, and thatsuch illustration therefore is not to be construed as in any way limiting the range of use of the device.

A relief valve of the type disclosed in my 00- pending application and as illustrated in Fig. 1 of the present drawing, comprises a casing A inclusive of a pair of cylinders or chambers 10 and 11 disposed in side to side relation with'their interiors connected with one another by a lateral passage 12, the chamber IObeing adapted for connection with a volatile liquidstorage tank 1 (not shown) by means of a pipe 13, for ex ample, and the chamber 11 having a pair of valves 14 and 15 disposed'therein to respectively control the escape of vapor from the tank and the inlet of air to the tank through a vent opening in the lower. end of the valve chamber 11.

The present fire screen device is composed'of a pluralityof duplicate ring-like plates 16 formed 5 preferably'from suitable rustproof metal such as aluminum, and in accordance with the invention each or these plates is provided, preferably near its periphery, with a plurality of circumferentially spaced rivet receiving apertures 17 and, between each adjacent pair of said apertures, with other fastener receiving apertures 18.

In forming the plates 16 the rivet receiving apertures 17 preferably are punched therein, and during this operation a suitable die or dies preferably is or are employed to deflect the metal of the plate directly surrounding each of said openings laterally beyond the plane of one side of the plate, thereby to provide, in surrounding relation to each of said apertures, a spacing bead or protuberance 19. However, the apertures 1'7 and the beads 19 may be formed in any other manner and any other suitable spacing means may be provided in lieu of the beads 19.

Also in forming the plates 16 the metal of each plate preferably is deflected laterally at suitably spaced points in the same direction as the beads 19 to provide other spacing protuberances 20, which protuberances are arranged preferably in two concentric series, those of one series being disposed in pairs one to either side of each aperture 18, and those of the other series being disposed adjacent to the central-opening 21 in the plate, the result being that the several protuberances of each plate are disposed in staggered relation.

To construct a fire screen unit from the plates 16, a desired number of said plates are superimposed upon one another with the apertures 1'7 and 18 of the several plates disposed in alinement with one another and with the protuberances of the respective plates all facing in the same direction, whereby the plates are held by said protuberances in slight spaced relation, thus to provide a narrow slit 22 between each adjacent pair of said plates. In addition, a flat closure plate 23 is disposed against one of the end plates of the unit, and the several plates 16 and the closure plate 23 then are secured together in a unitary assembly by means of preferably hollow rivets 24 passed through the apertures 17 of the several plates 16 and through alined apertures in the plate 23.

The rivets 2 1 serve to hold the plates of the unit with the fastener receiving apertures 18 of the plates 16 in alinement with one another and in alinement with corresponding apertures formed in the closure plate 23, and thus, to secure the unit in covering relation to the vent opening in the lower end of the chamber 11 of the valve casing A, all that is necessary is to pass bolts 25 through the fastener receiving openings of the unit and thread said bolts into thread- -ed apertures previously provided in the casing A.

In the unitary assembly of the plates 16 and 23, it is apparent that the central openings 21 of the plates 16 aline with one another to provide a central passage through the unit, which 4.0

passage opens through the inner end of the unit and is closed at the outer end of the unit by the plate 23. With the unit secured in covering relation to the vent opening in the valve casing A it thus follows that air is permitted to pass freely through the slits 22 between the various plates of the unit into the central passage in the unit and through the valve A to the liquid storage tank to relieve any partial vacuum which may tend to form in the tank, and that likewise,

, to the vent opening of the valve A is eliminated.

Preferably, a wire screen 26 of suitably fine mesh is interposed between the inner end of the fire screen unit and the valve A to exclude dust and other foreign matter from the valve chamber. Preferably, too, the lower end of the valve casing A is formed with a depending annular lip 27 disposed outwardly of the fire screen unit for the purpose of causing rain water and the like to drip from the valve casing withoutcontact with the fire screen Lmit. The use of a screen 26 and the provision of the lip 27 are optional considerations, however, as will be understood.

In view of the foregoing it will be apparent,

' as heretofore stated, that the present unit may be used either with other types of relief valves or in direct covering relation to the vent opening of a tank. It will likewise be apparent that the size and shape of the unit may be varied to suit particular conditions of use thereof, and that various modifications of the specific structural arrangement illustrated may be resorted to within the spirit and scope of the invention as defined in the appended claims.

1. A flame screen unit comprising a series of ring-like plates disposed in superimposed relation, each plate having a plurality of openings to receive fasteners for securing the plates together and further having other openings to receive fasteners for securing the unit in covering relation to a tank vent opening, protuberances integral with said plates surrounding each of said first mentioned openings of each plate to hold the plates in slight spaced relation in the vicinity of said openings, other protuberances carried by each plate serving to hold other portions of the plates in spaced relation, all of said protuber-' ances contacting directly with the next adjacent plate, a closure member for one end of the unit, and fasteners extending. through said closure memberand through said first mentioned openings to secure the plates and said closure member in assembly with one another.

2. The combination with a tubular member having one side communicating with a storage vessel for volatile liquids and having its other side communicating with the atmosphere, of a flame arrester device arranged at the atmosphere side of said tubular member and capable of preventing propagation of fiame from the exterior to the interior thereof, said device comprising a stack of spaced-apart plates having their outer edges exposed directly to the atmosphere, and each of said plates having a central opening providing a passageway communicating with said tubular member, and an exposed cover member fitted to the outermost plate of the stack to close said passageway.

JOHN J. TOKHEIM.

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